Stator core with a strucuture to improve assembly characteristics

ABSTRACT

Disclosed stator core for motor is comprising: more than one stator core body; a fixing unit, which is arranged at both ends of the stator core body and fixes the stator core body to be a cylindrical shape; a first insulator, which is integrally formed by mold in order to wrap a part of the stator core body and a side surface of plural teeth simultaneously; and a second insulator, which is arranged to have a form corresponding to the first insulator, and which is integrally formed by mold in order to wrap a part of the stator core body and a side surface of plural teeth simultaneously through the assembly with the first insulator, wherein the first simulator and the second simulator are separated from each other by the section wrapping the teeth during the bending process of the stator core body.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. §119 of KoreanPatent Application No. 10-2011-0107389, filed Oct. 20, 2011, which ishereby incorporated by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present invention relates stator core for motor and manufacturingmethod thereof.

2. Description of the Related Art

Generally, stator core for motor is formed by coiling plural teethprotruded from an inner circumferential surface after a metal core bodyis configured as a cylindrical shape.

Recently the stator core needs a miniaturization and weight lighteningaccording to a miniaturization of motor, thus a forming the stator coreby laminating a thin metal plate with constant thickness or forming thecylindrical shaped stator core by combining a roughly “T” shaped a splitcore having one teeth is more often used than a conventional formingmethod using the stator core of one body.

But for the laminating stator core, there is a complication that pluralmetal plates undergo press working with the same configuration, and thenthe laminating process should be done separately. Further for the splitcore, there is a complication that stator core should be formed as acylindrical shape by a fitting combination for the connecting part ofsplit core using an extra adhesion or arranging a complementary shapedue to an air gap in a assembly position for each split core during acombination process of a cylindrical shaped stator core by combinationof each split core after each split core is formed by molding orsintering.

Recently for the solution of the described complication, the art whichassembles more than one laminated unit core with completion of bendingafter laminating plural unit core and bending laminated unit coresimultaneously, to be ring shaped stator core is stated in the KoreanPatent No. 2008-0078944, released on Aug. 29, 2008.

But according to this composition, product defects by the separation ofcore assembly are mostly likely to occur in a assembly process of statorcore after bending, and also there is a problem that if the assembledparts are not firmly fixed, the efficiency for motor can fall or poorperformance can occur.

BRIEF SUMMARY

Accordingly, an object of the present invention is to provide the statorcore for motor, which has improved structure in order to compose acylindrical stator core by rolling one integrally formed body, andfirmly compose an assembly structure in the assembly units facing eachother.

The stator core for motor by the present invention comprises that morethan one stator core body, which is formed as one body by mold forplural teeth to be formed protrusively at regular interval in the samedirection, and is formed as cylindrical shape in which both ends arecombined by bending process for a designed section of right and leftaround the teeth; a fixing unit, which is arranged at both ends of thestator core body and fixes the stator core body to be a cylindricalshape; a first insulator, which is integrally formed by mold in order towrap a part of the stator core body and a side surface of plural teethsimultaneously; and a second insulator, which is arranged to have a formcorresponding to the first insulator, and which is integrally formed bymold in order to wrap a part of the stator core body and a side surfaceof plural teeth simultaneously through the assembly with the firstinsulator, wherein the first simulator and the second simulator areseparated from each other by the section wrapping the teeth during thebending process of the stator core body.

Preferably, but not necessarily, the first insulator and the secondinsulator have the bottleneck having within 0.5 mm thickness nearby theposition of the bending section of the stator core body, and thebottleneck is fractured by fatigue during the bending process of thestator core body.

Preferably, but not necessarily, the fixing unit comprises a fixingprotrusion, which is protrusively formed at one side end of the statorcore body; and a fixing groove, which is concavely formed ascomplementary shape to the fixing protrusion at the other end of thestator core body.

Further, the fixing unit comprises a pin groove, which is formed at bothends of the stator core body; and a fixing pin, which is fittedadjustably to the pin groove. The pin groove comprises more than twohitching units; and an opening unit connected with the hitching unit,and can inhibit the fixing pin from being separated in the perpendiculardirection to the direction of which the fixing pin is inserted andassembled in the pin groove, herein the pin groove is arranged as a “T”shape, and the fixing pin fixedly inserted in a pair of the pin grooveis arranged as a “H” shape.

Preferably, but not necessarily, each corner of the fixing pin and pingroove are rounded, and the fixing pin is arranged as same thicknesswith the stator core body.

Preferably, but not necessarily, the stator core body has a hook unithaving complementary shape around the protrusion of the adjacent teethin order to maintain a cylindrical shape in the bending process.

Preferably, but not necessarily, the hook unit has the rounded edge ofwhich the concavo and convex structure interlocked with each other, andthe gapped groove is formed at the position nearby the hook unit toreduce an interference effect during the bending of stator core body.

According to an exemplary embodiment of the present disclosure, themanufacturing method of stator core for motor comprises a stage ofinjection molding for more than one stator core body, which is formed asone body by mold for plural teeth to be formed protrusively at regularinterval in the same direction, and is formed as cylindrical shape inwhich both ends are combined by bending process for a designed sectionof right and left around the teeth; a stage of injection molding for afirst insulator, which is integrally formed by mold in order to wrap apart of the stator core body and a side surface of plural teethsimultaneously, and for a second insulator, which is arranged to have aform corresponding to the first insulator, and which is integrallyformed by mold in order to wrap a part of the stator core body and aside surface of plural teeth simultaneously through the assembly withthe first insulator; a stage of assembly for the molded stator corebody, the first insulator, and the second insulator in a linearcondition; a stage of coiling around the teeth insulated by the firstinsulator and the second insulator; a stage of fixing the coiled statorcore body, the first insulator, and the second insulator by using thefixing unit arranged at the both ends of the stator core body afterbending the coiled stator core body, the first insulator, and the secondinsulator as a circular shape.

The stage of bending further comprises a stage of fixing for every teethby the section successively through the hook unit, which is configurednearby the stator core body, and has complementary shape around theprotrusion of the adjacent teeth.

The stage of coiling comprises a stage of coiling the teeth in order tomaintain the constant distance between the coils wound around the teethof stator core body having a cylindrical shape by the bending process.

Preferably, but not necessarily, the manufacturing method of stator corefor motor comprises a stage of forming a cylindrical shaped stator coreby assembly with another stator core module formed from the equalprocess, if the stator core module formed by the assembly and bending ofthe stator core body, the first insulator, and the second insulator, hasa semicircular shape.

The advantage according to the present invention is that the fixingability and assembly efficiency can be improved because the reliabilityof assembly part of stator core made by rolling one integrally formedbody is improved.

Further, the combination and transportation for motor is easy and theloss of working following combination error of core unit can be reducedbecause the air gap of each split cores is minimized during thecombination of stator core.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view illustrating the stator core, thefirst insulator and the second insulator. The stator core is formed in amold and assembled, further, has a state before bending;

FIG. 2 is an assembly view of FIG. 1;

FIG. 3 is a perspective view illustrating the stator core of FIG. 1,which is bended and is cylindrically rolled, and as a fixing unitaccording to the first exemplary embodiment of the present disclosure;

FIG. 4 is a perspective view illustrating the stator core of FIG. 1,which is bended and is cylindrically rolled, and as a fixing unitaccording to the second exemplary embodiment of the present disclosure;

FIG. 5 is a perspective view illustrating the stator core module of FIG.1, which is bended and is cylindrically rolled;

FIG. 6 is a perspective view of the stator core module according to anexemplary embodiment of the present disclosure;

FIG. 7 is an exploded perspective view of FIG. 6;

FIG. 8 is a plan view of the stator core of FIG. 6 and an enlarged viewof the teeth; and

FIG. 9 and FIG. 10 are flow charts illustrating the manufacturing methodof the stator core for the motor according to an exemplary embodiment ofthe present disclosure.

DETAILED DESCRIPTION

Hereinafter, the stator core for motor and manufacturing method thereofwill be described in detail with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view illustrating the stator core, thefirst insulator and the second insulator, and the stator core is formedin a mold and assembled, further, has a state before bending, FIG. 2 isan assembly view of FIG. 1, FIG. 3 is a perspective view illustratingthe stator core of FIG. 1, which is bended and is cylindrically rolled,and as a fixing unit according to the first exemplary embodiment of thepresent disclosure, FIG. 4 is a perspective view illustrating the statorcore of FIG. 1, which is bended and is cylindrically rolled, and as afixing unit according to the second exemplary embodiment of the presentdisclosure, FIG. 5 is a perspective view illustrating the stator coremodule of FIG. 1, which is bended and is cylindrically rolled, FIG. 6 isan enlarged view of the teeth for stator core module in FIG. 5.

As shown in FIG. 1 or FIG. 4, the stator core of the present inventioncomprises the stator core module (1) composed of assembly with thestator core body (100), the first insulator (410), and the secondinsulator (420), and wound by the coil (C, referring FIG. 8), andfurther comprises the fixing units (200) (300) for fixing the bendedstator core body (100) as a circular shape.

The stator core body (100) is formed as one body by mold for pluralteeth (110) to be formed protrusively at regular interval in the samedirection. Preferably, but not necessarily, the stator core body (100)is formed as cylindrical shape in which both ends (101) (102) arecombined by bending process for a designed section (A) of right and leftaround the teeth (110) as shown in FIG. 2.

Preferably, but not necessarily, the stator core body (100) has a hookunit (120) having complementary shape around the protrusion of theadjacent teeth (110) in order to maintain a cylindrical shape in thebending process.

The hook unit (120) has a concavo and convex structure interlocked witheach other. The hook protrusion (121) is formed at the one end, and thereceptive groove (122) is formed at the other end of the hook unit(120). Preferably, but not necessarily, the edges of the hook protrusion(121) and the receptive groove (122) are rounded for smooth combination.

Further, the gapped groove (123) is formed at the position nearby thehook unit (12) to reduce an interference effect of each designed section(A) during the bending of stator core body (100). Preferably, but notnecessarily, the gapped groove (123), as shown in FIG. 1, has a trenchstructure having a roughly circular cross section and one end is openedthus this opened end is connected with the hook unit (120).

According to the first exemplary embodiment of the present disclosure,the fixing unit (200), as shown in FIG. 3, is formed at the both ends ofthe stator core body (100) in order to fix the stator core body (100) asa cylindrical shape, and comprises the fixing protrusion (210) and thefixing groove (220).

The fixing protrusion (210) is protrusively formed at the one end (101)of the stator core body (100), and is formed to have a roughly squarecross section as shown, but it is not limited to the square crosssection, further the cross section can have a circular or polygonalshape even though those are not shown. The fixing protrusion (210) canhave whatever structures if the fixing protrusion (210) is hooked in theseparation direction of the fixing groove (220).

The fixing groove (220) is concavely formed as a complementary shape tothe fixing protrusion (210) at the other end (102) of the stator corebody (100).

According to the first exemplary embodiment of the present disclosure,the fixing unit (200) configured in the same manner as above, is fixedby a sliding-fit assembly of the fixing protrusion (210) and the fixinggroove (200), and the fixing unit (200) fixes the stator core body (100)as a cylindrical shape by press-in process of minimizing a tolerancebetween the fixing protrusion (210) and the fixing groove (200).

According to the second exemplary embodiment of the present disclosure,the fixing unit (300) comprises, as shown in FIG. 4 and FIG. 5, a pingroove (310) and a fixing pin (320).

The pin groove (310) is formed at both ends of the stator core body(100), as shown, and comprises more than two hitching units (311) and anopening unit (312) connected with the hitching unit (311), and inhibitsthe fixing pin (320) from being separated in the perpendicular directionto the direction (Arrow B direction in FIG. 5) of which the fixing pin(320) is inserted and assembled in the pin groove (310).

According to an exemplary embodiment of the present disclosure,preferably, but not necessarily, the pin groove (310) is installed tohave a mutually symmetrical shape at the both ends (101) (102)(Referring FIG. 1) of the stator core body (100).

The fixing pin (320) has a complementary shape to a shape of the pingroove (310) to be inserted and assembled in the pin groove (310).Preferably, but not necessarily, the fixing pin (320) has a bilateralsymmetrical shape because the pin groove (310) located at the both ends(101) (102) of the stator core body (100) has a mutually symmetricalshape. The fixing pin (320) is pressed and assembled in the paralleldirection to the arrow B direction of FIG. 6.

According to an exemplary embodiment of the present disclosure, the pingroove (310) is arranged as a “T” shape, and the fixing pin (320)fixedly inserted in a pair of the pin groove (310) is arranged as a “H”shape, but it is not limited to the described shapes, further the shapescan have whatever shapes if the shape can inhibit the separation in theperpendicular direction to the described arrow B direction.

Further preferably, but not necessarily, each corner of the pin groove(310) and the fixing pin (320) are rounded, and are arranged as samethickness with the stator core body (100).

By means of the fixing unit (300) using the fixing pin (320), thecombination and transportation for motor is easy and the loss of workingfollowing combination error of core unit can be reduced because the airgap of each split cores is minimized during the combination of statorcore.

The first insulator (410) and the second insulator (420), as shown inFIG. 1, FIG. 2, FIG. 7, and FIG. 8, are connected at the upper and thelower of the stator core body (100), and inhibit a current flowing inthe coil (C) wound in the teeth (110) from being transmitted to thestator core body (100).

The first insulator (410) and the second insulator (420) are arranged asmutually complementary shapes, and assembled with the stator core body(100) at the same time. Preferably, but not necessarily, for the abovedescribed assembly, the first insulator (410) and the second insulator(420), as shown in FIG. 1 and FIG. 2, are formed as one body having aline shape by injection molding.

Preferably, but not necessarily, the first simulator (410) and thesecond simulator (420) are arranged to be separated from each other bythe section wrapping the teeth (110) during the bending process of thestator core body.

Preferably, but not necessarily, the first insulator (410) and thesecond insulator (420), as shown in FIG. 1 and FIG. 2, have thebottleneck (411) (421) having within 0.5 mm thickness nearby theposition of the bending section of the stator core body (100), and thebottleneck (411) (421) is fractured by fatigue during the bendingprocess of the stator core body (100).

According to the described composition, the first No. 1 insulator (410a) and the second No. 1 insulator (410 b), which are attached each otherwhen first created, can form neck unit (N) by separation as shown inFIG. 8 if the stator core module (1) is bended as cylindrical shape.

Hereinafter, the manufacturing method of stator core for motor will bedescribed in detail according to an exemplary embodiment of the presentdisclosure.

An object of the present invention is to form the stator core body(100), the first insulator (410), and the second insulator (420) as aline shape for the manufacturing of the stator core module (1), and isto form the temporarily assembled stator core module (1), as shown inFIG. 2, by the combination of the stator core body (100), the firstinsulator (410), and the second insulator (420).

First, one body by mold is formed for plural teeth protrusively atregular interval in the same direction. More than one stator core body,preferably two stator core bodies (100) are formed by injection orsintering as cylindrical shape in which both ends are combined bybending process for a designed section of right and left around theteeth. The opposite surface of the teeth formed is configured to have acircular shape and have an arc shape by a constant interval (S10).

The first insulator (410) and the second insulator (420) are integrallymade by injection molding to have complementary shape to each other, andto wrap a part of stator core body (100) and one end surface of theplural teeth (110) simultaneously. Preferably, but necessarily, thefirst insulator (410) and the second insulator (420) are made ofsynthetic resins often used as insulating material (S20).

The line-shaped stator core module (1) is formed by the assembly withthe stator core body (110), the first insulator (410), and the secondinsulator (420), which all are formed from the (S10) stage and the (S20)stage, in a line condition which is previous stage of bending.

As a next stage, the coil (C, Referring FIG. 8) is wound on the teeth(110) insulated by the first insulator (410) and the second insulator(420) of the line-shaped stator core module (10) formed from the (S30)stage. Though the described coiling, more simple coiling can be donecomparing to a coiling process that coils on the teeth of an integratedstator core of existing. In other words, in order to make a uniformdistance (g) (Referring FIG. 8) with the coil on the adjacent teeth(110) after bending, the end of the teeth (110) has a small number ofturns, and the other end has a large number of turns. In the pas ways,it is difficult to wind a coil due to a small space between the teethprotruding toward the center because the stator core is already formedas a cylindrical shape. But it is easy to wind a coil as much as wantedby location, if a coil is wound in an unfolded condition as aline-shaped. Further, the space factor of stator core module (1) can beimproved because it is possible to make a uniform distance (g) with thecoil (C) on the adjacent teeth (110) after bending (S40).

For the stator core module (1) coiled from the (S40) stage, the statorcore body (100), the first insulator (410), and the second insulator(420) is fixed by the fixing units (200) (300) arranged ate the bothends of the stator core body after bending the stator core body (100),the first insulator (410), and the second insulator (420) as a circularshape (S50).

The stage of bending further comprises a stage (S51) of fixing for everyteeth by the section successively through the hook unit (120), which isconfigured nearby the stator core body (100), and has complementaryshape around the protrusion of the adjacent teeth, and a stage (S52) offorming the separated neck unit (N) (Referring FIG. 8) through thefatigue fracture, which is caused by bending, for the bottleneck (411)(421) of the first insulator (410) and the second insulator (420).

If the stator core module (1), which is formed by the assembly andbending of the stator core body (100), the first insulator (410), andthe second insulator (420), is arranged as a semicircular shape, thecylindrical-shaped stator core can be formed by combination with theanother stator core module (1) made from the stage of (S10) or (S50).According to an exemplary embodiment of the present disclosure, thecylindrical-shaped stator core body (100) is formed by the combinationof the two semicircular-shaped stator core modules (1). But it is notlimited to the above described, further it is possible to combine morethan two stator core modules (1) as needed. Preferably, but notnecessarily, the stator core body (100) is combined by using just one ortwo stator core module (1) because there is no difference with aconventional combination process using split core if the number of thestator core module (1) increases.

Although the present disclosure has been described with reference to anumber of illustrative embodiments thereof, it should be understood thatnumerous other modifications and embodiments can be devised by thoseskilled in the art that will fall within the spirit and scope of theprinciples of this disclosure.

More particularly, various variations and modifications are possible inthe component parts and/or arrangements of subject combinationarrangement within the scope of the disclosure, the drawings and theappended claims. In addition to variations and modifications in thecomponent parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A stator core with a structure to improveassembly characteristics, the stator core comprising: at least onestator core body formed as one body by mold for plural teeth to beformed protrusively at regular intervals in the same direction, whereinthe stator core body is formed in a cylindrical shape in which both endsare coupled to each other for a designed section of right and leftaround the teeth; a fixing unit arranged at both ends of the stator corebody for fixing the stator core body in a cylindrical shape; a firstinsulator integrally formed by a mold in order to wrap a part of thestator core body and a side surface of plural teeth simultaneously; anda second insulator arranged to have a form corresponding to the firstinsulator, wherein the second insulator is integrally formed by a moldin order to wrap a part of the stator core body and a side surface ofplural teeth simultaneously through the assembly with the firstinsulator, wherein the first insulator and the second insulator areseparated from each other by the section wrapping the teeth, wherein thefirst insulator and the second insulator have a bottleneck nearby aposition of a bending section of the stator core body, and wherein thebottleneck is configured to be fractured by fatigue, and wherein thebottleneck has a thickness of 0.5 mm or less.
 2. The stator core ofclaim 1, wherein the fixing unit comprises: a fixing protrusion, whichis protrusively formed at one side end of the stator core body; and afixing groove, which is concavely formed as a complementary shape to thefixing protrusion at the other end of the stator core body.
 3. Thestator core of claim 1, wherein the fixing unit comprises: a pin groove,which is formed at both ends of the stator core body; and a fixing pin,which is fitted adjustably to the pin groove.
 4. The stator core ofclaim 3, wherein the pin groove inhibits the fixing pin from beingseparated in the perpendicular direction to the direction in which thefixing pin is inserted and assembled in the pin groove, and comprises:more than two hitching units; and an opening unit connected with thehitching unit.
 5. The stator core of claim 3, wherein the pin groove isarranged as a “T” shape, and the fixing pin fixedly inserted in a pairof the pin grooves is arranged as an “H” shape.
 6. The stator core ofclaim 5, wherein each corner of the fixing pin and pin groove arerounded.
 7. The stator core of claim 3, wherein the fixing pin has thesame thickness as the stator core body.
 8. The stator core of claim 1,wherein the stator core body has a hook unit having a complementaryshape around a protrusion of the adjacent teeth maintaining thecylindrical shape thereof.
 9. The stator core of claim 8, wherein thehook unit has a rounded edge of which a concavo and convex structureinterlock with each other.
 10. The stator core of claim 8, wherein agapped groove is formed at a position nearby the hook unit to reduce aninterference effect during the bending of the stator core body.